Various types of magnetic field sensing elements are known, including Hall effect elements and magnetoresistance elements. Magnetic field sensors generally include a magnetic field sensing element and other electronic components.
Some magnetic field sensing elements and associated magnetic field sensors provide an electrical signal representative of a direction of a sensed magnetic field. The magnetic field signal varies in accordance with the direction in a way that can be resolved to identify a pointing direction of the magnetic field.
Most types of such direction-indicating magnetic field sensing elements and associated magnetic field sensors generate signals that are indicative of the direction of a component of the magnetic field in only two dimensions, i.e., in a plane. However, the magnetic field may have a pointing direction not parallel to the plane of sensitivity of the magnetic field sensor, i.e., in three dimensions.
Magnetic field sensor that can sense three dimensions of a magnetic field are useful in some applications, for example, in three dimensional joysticks, where the joystick can be moved in two dimensions and also can be depressed in a third dimension. Some three-dimensional applications use both a magnetic field sensor operable to provide a two-dimensional indication of a pointing direction of a magnetic field in a plane and also a separate one-dimensional magnetic field sensor operable to provide indication of a magnitude of a magnetic field in a direction perpendicular to the plane.
Thus, to resolve some of the three-dimensional characteristics of the magnetic field, some arrangements use both a two-dimensional magnetic field sensor and also a one-dimensional magnetic field sensor. In some applications, output signals from the two magnetic field sensors can be further processed to provide a signal representative of a magnitude of the magnetic field along the three-dimensional pointing direction of the magnetic field. Thus, by combining information generated by the two magnetic field sensors, three-dimensional characteristics of the magnetic field can be determined.
It is cumbersome to provide both the above-described two-dimensional magnetic field sensor and also the above described one-dimensional magnetic field sensor. A combination of two such magnetic field sensors tends to be expensive. Furthermore, additional processing is required to resolve the three-dimensional characteristics of the sensed magnetic field. Still further, alignment of the two types of magnetic field sensors to provide orthogonal axes is critical to the accuracy of the resulting resolved three-dimensional characteristics, and such alignment can be difficult and inaccurate.
Therefore, it would be desirable to provide a single integrated magnetic field sensing element and associated magnetic field sensor that can generate a signal or signals that is/are indicative of characteristics of a magnetic field in three dimensions. In some embodiments, the integrated magnetic field sensing element is formed upon a single substrate, e.g., a silicon substrate, which tends to make it easier to provide aligned axes.